Which of the following pairs of values (x, y) maximizes the function $f ( x , y ) = x + 3 y$ subject to the constraint $x ^ { 2 } + 9 y ^ { 2 } = 72$ assuming x and y are positive?
(I) (-6, -2)
(II) $\left( 8 , \sqrt { \frac { 8 } { 9 } } \right)$
III) (2, -6)
(IV) (6, 2)
A) III only
B) I and II
C) IV only
D) I only
E) none of these

Question

Which of the following pairs of values (x, y) maximizes the function $f ( x , y ) = x + 3 y$ subject to the constraint $x ^ { 2 } + 9 y ^ { 2 } = 72$ assuming x and y are positive? 
(I) (-6, -2)  
(II) $\left( 8 , \sqrt { \frac { 8 } { 9 } } \right)$  
III) (2, -6)  
(IV) (6, 2)
A) III only 
B) I and II 
C) IV only 
D) I only 
E) none of these

Quizplus · Accepted Answer

The Answer of Which of the following pairs of values (x, y) maximizes the function $f ( x , y ) = x + 3 y$ subject to the constraint $x ^ { 2 } + 9 y ^ { 2 } = 72$ assuming x and y are positive? 
(I) (-6, -2)  
(II) $\left( 8 , \sqrt { \frac { 8 } { 9 } } \right)$  
III) (2, -6)  
(IV) (6, 2)
A) III only 
B) I and II 
C) IV only 
D) I only 
E) none of these

Which of the Following Pairs of Values (X, Y) Maximizes f(x,y)=x+3yf ( x , y ) = x + 3 yf(x,y)=x+3y

Which of the Following Pairs of Values (X, Y) Maximizes $f ( x , y ) = x + 3 y$